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versión On-line ISSN 2078-5135versión impresa ISSN 0256-9574

SAMJ, S. Afr. med. j. vol.104 no.1 Cape Town ene. 2014

EDITOR'S CHOICE

A 'new-look' SAMJ

The SAMJ now sports an educational component, resembling the BMJ, NEJM and Lancet, by incorporating CME. A review article[1] introduces readers to this month's subject matter on mental health and we include summaries of the additional articles that may be accessed online.

The clashing epidemics of HIV and TB

Francois Venter, one of South Africa (SA)'s foremost HIV scientists, reveals in our guest editorial just how far SA has progressed in controlling the epidemic since our 'AIDS denialism' days.

Progress, arguably, would have been yet greater had SA not had to contend with the two clashing epidemics of HIV and tuberculosis (TB).

The relationship between HIV and TB is bi-directional: TB is a catalyst in the progression of HIV and HIV infection is associated with an increased risk of developing TB. HIV infection alters the clinical presentation of TB such that TB progresses more rapidly and aggressively in HIV-positive individuals, making diagnosis difficult.

Extrapulmonary TB (EPTB) occurs in 20 - 70% of HIV-infected patients with TB and is most prevalent in the 25 - 44-year age group. Karstaedt[2] demonstrates that the most common sites of EPTB are the pleura, lymph nodes, bacteraemia, meningitis and peritonitis. Disseminated TB occurred in 25% of the patients in this study.

Sputum smears, which are the cornerstone of diagnosis in resource-limited settings, are usually negative in HIV-associated TB, contributing to a delay in commencing treatment. Fine needle aspiration biopsy (FNAB) of accompanying lymphadenitis provides a means of easy access to diagnostic material in many of these pulmonary cases. With this approach, Razack et al.[3] were able to confirm mycobacterial lymphadenitis (bacterial confirmation) in 80% of patients.

Of TB infections, 1% affect the spine. Yet, of patients treated for spinal TB, only 55% have a definitive laboratory diagnosis (dependent on the identification of the TB bacilli by Ziehl-Neelsen staining in bone biopsy specimens). Watt and Davis[4] stress that in patients with HIV, and more specifically AIDS, the histological changes can range from the classical caseating granulomas to a non-specific chronic inflammatory reaction without necrosis. Unexpectedly, the highest culture yield observed in their study came from samples showing non-necrotising chronic inflammatory changes and not from samples showing necrotising granulomas. Confirming the diagnosis histologically is but half the battle, as sensitivity to first-line drugs has still to be proven.

SA has one of the highest worldwide incidences of multidrug-resistant (MDR)-TB, owed significantly to HIV co-infection. Almost a quarter of patients requiring treatment of their MDR-TB have symmetrical symptomatic peripheral neuropathy (SSPN) as the study by Conradie et al.[5] confirms. To avoid renal failure in such patients, due to the combined nephrotoxicity of aminoglycosides and tenofovir, stavudine is often used. Exposure to stavudine is a well-documented risk factor for SSPN and Conradie et al. warn that the use of twice-daily stavudine for 6 months could potentially result in the development or exacerbation of SSPN.

Management of chronic pain

Chronic pain affects around one in five patients in primary care, occurring more frequently in older individuals, whose presentation is complicated by age-related physiological changes, comorbidities and multiple medications. Chronic pain impacts quality of life, yet may be difficult to manage, and sufferers are more likely to report anxiety or depression.

The South African guideline for the use of chronic opioid therapy for chronic non-cancer pain (CNCP)[6] developed by a multi-disciplinary panel provides recommendations for patient selection and the use of opioids for CNCP. Appropriate patient selection is paramount, requiring a comprehensive physical and biopsychosocial assessment to establish the diagnosis and to guide management decisions.

Opioids are well accepted for the treatment of severe acute pain and chronic pain associated with cancer and at the end of life, but less is known about their efficacy and safety with long-term use for CNCP. Nevertheless, limited evidence indicates that they can be effective therapy for a carefully selected group of patients as part of a wider management plan focused on reducing disability and improving quality of life.